Final answer:
If a GUT is proven and the four forces are unified, the orbit of the moon is still determined by the gravitational force. GUT unification mainly affects subatomic particles and does not apply to celestial bodies. GUT does not negate classical physics laws.
Step-by-step explanation:
If a Grand Unified Theory (GUT) is proven and the four forces are unified, it will still be correct to say that the orbit of the moon is determined by the gravitational force. GUT unification changes the fundamental forces, but it does not apply to celestial bodies.
The unification of forces in a GUT mainly focuses on the subatomic particles and their interactions at extremely small distances and high energies. The gravitational force, on the other hand, is a macroscopic force that governs the motion of celestial bodies such as the moon.
While GUT unification may provide a deeper understanding of the fundamental forces, it does not negate classical physics laws that explain the motion of larger objects like the moon in our solar system.